Photosensitive resin composition and photoresist ink for manufacturing printed wiring boards

ABSTRACT

A photosensitive resin composition developable with water or a diluted alkali solution comprises the following components (A) to (D). That is, the component (A) is a water-soluble photosensitive resin selected from the group consisting of a first resin obtained by introducing a styryl pyridinium group into a polyvinyl alcohol polymer, a second resin obtained by introducing a styryl quinolinium group into the polyvinyl alcohol polymer, and a third resin obtained by adding N-alkylol(meth)acrylamide to the polyvinyl alcohol polymer. The component (B) is a photosensitive prepolymer having a carboxyl group and at least two ethylenically unsaturated groups in molecule. The component (C) is a photopolymerization initiator. The component (D) is water. The photosensitive resin composition will be preferably used as a photoresist ink for manufacturing printed wiring boards.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a photosensitive resincomposition developable with water or a diluted alkali aqueous solution,and a photoresist ink for manufacturing printed wiring boards.

[0003] 2. Disclosure of the Prior Art

[0004] In the past, photoresist inks developable with a diluted alkaliaqueous solution have been used as inks for manufacturing printed wiringboards, screen printing stencils, color-filter pixels and color-filterprotective films, or a photogravure ink. For example, such photoresistinks are disclosed in Japanese Patent Early Publications No. 5-224413and No. 5-241340.

[0005] However, these photoresist inks contain various organic solventssuch that they can be uniformly applied on substrates. The organicsolvents are usually evaporated from the photoresist inks during apredrying step prior to a subsequent exposing step. Therefore, there areproblems inherent in the use of the organic solvents such as a poorworking condition, environmental pollution and the occurrence of a fire.

SUMMARY OF THE INVENTION

[0006] The present invention concerns a photosensitive resin compositiondevelopable with water or a diluted alkali aqueous solution, which iscapable of improving the above problems. The photosensitive resincomposition contains the following components (A) to (D). That is, thecomponent (A) is a water-soluble photosensitive resin selected from thegroup consisting of a first resin obtained by introducing a styrylpyridinium group into a polyvinyl alcohol polymer, a second resinalcohol polymer, and a third resin obtained by addingN-alkylol(meth)acrylamide to the polyvinyl alcohol polymer. Thecomponent (B) is a photosensitive prepolymer having a carboxyl group andat least two ethylenically unsaturated groups in molecule. The component(C) is a photopolymerization initiator. The component (D) is water.

[0007] It is preferred that the photosensitive resin composition furthercontains a photopolymerizable ethylenically-unsaturated monomer as thecomponent (E).

[0008] It is particularly preferred to use the photosensitive resincomposition of the present invention as a photoresist ink formanufacturing printed wiring boards.

[0009] These and still other objects and advantages will become apparentfrom the following detail descriptions of the preferred embodiments andexamples of the invention.

DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] In the present specification, “(meth)acrylic-” means “acrylic-”and “methacrylic-”. For example, (meth)acrylic acid means acrylic acidand methacrylic acid. In addition, (meth)acrylamide means acrylamide andmethacrylamide.

[0011] A photosensitive resin composition of the present inventioncomprises a water-soluble photosensitive resin (A), photosensitiveprepolymer (B), photopolymerization initiator (C) and water (D).

[0012] The water-soluble photosensitive resin (A) is selected from thegroup consisting of a water-soluble photosensitive resin (A1) obtainedby introducing a styryl pyridinium group or a styryl quinolinium groupinto a polyvinyl alcohol polymer, and a water-soluble photosensitiveresin (A2) obtained by adding N-alkylol(meth)acrylamide to the polyvinylalcohol polymer.

[0013] As the polyvinyl alcohol polymer used to prepare thephotosensitive resin (A), for example, it is possible to use a polyvinylalcohol obtained by complete saponification or a partial saponificationof polyvinyl acetate, or a water-soluble polyvinyl alcohol derivativeobtained by a reaction of —OH group or —OCOCH₃ group of acompletely-saponified or partially-saponified polyvinyl alcohol with anacid-anhydride containing compound, carboxy-group containing compound,epoxy-group containing compound, or an aldehyde-group containingcompound. In addition, it is possible to use a vinyl alcohol copolymerhaving vinyl alcohol units, which is obtained by the completesaponification or the partial saponification of polyvinyl acetate. Asthe copolymer component of vinyl acetate, for example, it is possible touse (meth)acrylic acid, (meth)acrylamide, N-methylol(meth)acrylamide,styrene, ethylene, propylene, maleic anhydride, (meth)acrylonitrile,(meth)acrylic ester.

[0014] It is preferred that the polyvinyl alcohol polymer contains 60mol % or more of the vinyl alcohol units within its polymerization unit.In particular, when using the polyvinyl alcohol polymer containing 80mol % or more of the vinyl alcohol units, or the polyvinyl alcoholobtained by the complete saponification of polyvinyl acetate, there isan advantage that the photosensitive resin composition of the presentinvention is excellent in the water-solubility.

[0015] The photosensitive resin (A1) can be prepared by a conventionalmethod disclosed in, for example, Japanese Patent Early Publication[KOKAI] No. 55-23163, No. 55-62905, or No. 56-11906.

[0016] Concretely, for example, the photosensitive resin (A1) can beobtained by adding a formyl styryl pyridinium salt or a formyl styrylquinolinium salt to the polyvinyl alcohol polymer according to an acetalreaction applying an alcoholic —OH group of the polyvinyl alcoholpolymer.

[0017] The general formula (1) shows a typical structure of anintroduced portion of the styryl pyridinium group in the photosensitiveresin (A1). The general formula (2) shows a typical structure of anintroduced portion of the styryl quinolinium group in the photosensitiveresin (A 1).

[0018] In these formulas (1) and (2), each of R1 and R2 is hydrogenatom, alkyl group, or aralkyl group, “X⁻” is a conjugate base of anacid, “m” is an integer of 1˜6, and “n” is 0 or 1.

[0019] It is preferred that an introduction rate of the styrylpyridinium group or the styryl quinolinium group in the photosensitiveresin (A1) is within a range of 0.3 to 20 mol %, and more preferably 0.5to 10 mol %, per vinyl alcohol polymerization unit constructing thephotosensitive resin (A1). In the range of 0.3 to 20 mol % of theintroduction rate, the photosensitive resin (A1) is good in thewater-solubility, and has a suitable photo-bridging capability.

[0020] The water-soluble photosensitive resin (A2) can be prepared by aconventional method disclosed in, for example, Japanese PatentPublication [KOKOKU] No. 49-5923, or Japanese Patent Early Publication[KOKAI] No. 62-267302.

[0021] Concretely, for example, the photosensitive resin (A2) can beobtained by an etherification reaction between a polyvinyl alcoholpolymer and N-alkylol(meth)acrylamide in the presence of an acidcatalyst such as inorganic acid or sulfonic acid derivative in a goodsolvent of the polyvinyl alcohol polymer such as water or a N-methylpyrrolidone solution, or a suspension of a bad solvent of the polyvinylalcohol polymer.

[0022] As the N-alkylol(meth)acrylamide, for example, it is possible touse N-methylol(meth)acrylamide, N-ethylol(meth)acrylamide,N-propylol(meth)acrylamide, or N-butylol(meth)acrylamide. TheN-alkylol(meth)acrylamide can be one of these materials or can be acombination of two or more of these materials, if necessary.

[0023] It is preferred that an addition ratio of theN-alkylol(meth)acrylamide is within a range of 0.05 to 25 mol %, andmore preferably 0.05 to 15 mol %, per vinyl alcohol polymerization unitconstructing the photosensitive resin (A2). In the above range of theaddition ratio, (A2) can be obtained.

[0024] The photosensitive prepolymer (B) is a photosensitive prepolymerhaving a carboxyl group and at least two ethylenically unsaturatedgroups in molecule. The photosensitive prepolymer is characterized inthat a plurality of groups having photopolymerizableethylenically-unsaturated groups branch from a main chain of theprepolymer. Since the photosensitive prepolymer contains the carboxylgroup, it can be swelled, dispersed or dissolved in a diluted alkaliaqueous solution. However, when the photosensitive prepolymer is exposedin the presence of the photopolymerization initiator, the ethylenicallyunsaturated groups of the prepolymer molecules react each other toincrease the molecular weight, so that the dispersing property or thesolubility to the diluted alkali aqueous solution lowers.

[0025] Therefore, a film made of the photosensitive resin composition ofthe present invention containing the photosensitive prepolymer (B) canbe swelled, dispersed or dissolved in the diluted alkali aqueoussolution before the exposing step. However, after the film is cured bythe exposing step according to photopolymerization, the dispersingproperty or the solubility to the diluted alkali aqueous solutionlowers. Therefore, by applying a difference of the solubility of thephotosensitive resin composition to the diluted alkali aqueous solutionbefore and after the exposing step, it is possible to form a desiredpattern of a cured film of the photosensitive resin composition. Thatis, the film of the photosensitive resin composition is selectivelyexposed, and then developed with the diluted alkali aqueous solution.The non-exposed region of the film is washed away to leave the exposedregion of the film, so that the desired pattern of the cured film of thephotosensitive resin composition is obtained.

[0026] The cured film of the photosensitive resin composition can bestripped and removed by the use of sodium periodate. Additionally, sincethe photosensitive resin composition of the present invention containsthe photosensitive prepolymer (B) having the carboxyl group, the curedfilm can be stripped and removed by the use of an aqueous solution ofalkali-metal hydroxide.

[0027] It is preferred that the photosensitive prepolymer (B) itself canform a film. In the present invention, since the photosensitive resincomposition contains the photosensitive resin (A) and the photosensitiveprepolymer (B), there is an advantage that a predried film of thephotosensitive resin composition is substantially free from surfacetackiness, so that contamination of a phototool artwork with thephotosensitive resin composition can be prevented even when the artworkis directly put on the predried film.

[0028] It is preferred that an acid value of the photosensitiveprepolymer (B) is within a range of 20 to 300 mgKOH/g, and morepreferably 40 to 200 mgKOH/g. In this range of acid value, it ispossible to shorten the developing time when developing thephotosensitive resin composition with the diluted alkali aqueoussolution. In addition, since the resistance to diluted alkali aqueoussolution of the cured film of the photosensitive resin compositionadequately lowers, a better pattern of the cured film can be easilyformed.

[0029] It is also preferred that a weight-average molecular weight ofthe photosensitive prepolymer (B) is within a range of 2000 to 250000,and more preferably 4000 to 100000. In the above range of weight-averagephotosensitivity of the photosensitive resin composition. In addition,when the weight-average molecular weight is less than 2000, there is apossibility that the surface tackiness of the predried film occurs. Onthe other hand, as the weight-average molecular weight exceeds 250000,there is a tendency of lowering the developing property.

[0030] The carboxyl group of the prepolymer (B) may be neutralized by anorganic basic compound such as alkanol amine, alkali-metal hydroxide, oran inorganic basic compound such as ammonia.

[0031] As the prepolymer (B), for example, it is possible to use aphotosensitive prepolymer (B 1) obtained by adding an ethylenicallyunsaturated monocarboxylic acid and an unsaturated or saturatedpolybasic acid anhydride to a polyfunctional epoxy compound having atleast two epoxy groups.

[0032] As the polyfunctional epoxy compound of the prepolymer (B 1), forexample, it is possible to use a phenol novolac-type epoxy resin, cresolnovolac-type epoxy resin, bisphenol A-type epoxy resin, bisphenolA-novolac-type epoxy resin, bisphenol F-type epoxy resin,N-glycidyl-type epoxy resin, alicyclic-type epoxy resin (e.g.,“EHPE-3150” manufactured by Daicel Chemical Industries, Ltd.), tris(hydroxyphenyl) methane-based polyfunctional epoxy resin (e.g.,“EPPN-502H” manufactured by NIPPON KAYAKU Co., LTD. or “TACTIX-742” and“XD-905” manufactured by DOW CHEMICAL), dicyclopentadiene-phenol-typeepoxy resin, naphthalene-type epoxy resin. As the ethytenicallyunsaturated monocarboxylic acid, for example, it is possible to use(meth)acrylic acid.

[0033] As the unsaturated or saturated polybasic acid anhydride of theprepolymer (B1), for example, it is possible to use a dibasic acidanhydride such as succinic anhydride, methyl succinic anhydride, maleicanhydride, citraconic anhydride, glutaric anhydride, itaconic anhydride,phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl nadic acid anhydride,hexahydrophthalic anhydride, and methyl hexahydrophthalic anhydride, ora polybasic acid anhydride such as trimellitic acid anhydride,pyromellitic acid anhydride, benzophenone tetracarboxylic anhydride andmethyl cyclohexene tetracarboxylic anhydride.

[0034] In addition, as the prepolymer (B), it is possible to use aphotosensitive prepolymer (B2) obtained by a reaction of a compoundhaving a photoreactive ethylenically unsaturated group and a hydroxylgroup in molecule with a copolymer of an unsaturated polybasic acidanhydride such as maleic anhydride and an aromatic hydrocarbon having avinyl group such as styrene or vinyl alkyl ether.

[0035] As the compound of the prepolymer (B2), for example, it ispossible to use 2-hydroxyethyl(meth)acrylate,2-hydroxypropyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, diethyleneglycol mono(meth)acrylate, dipropylene glycol mono(meth)acrylate, ordibutylene glycol mono(meth)acrylate.

[0036] Moreover, as the prepolymer (B), for example, it is possible touse a photosensitive prepolymer (B3) obtained by a reaction of anethylenically unsaturated compound having a single epoxy group with acopolymer of a first ethylenically unsaturated monomer having nocarboxyl group and a second ethylenically unsaturated monomer having thecarboxyl group.

[0037] As the first ethylenically unsaturated monomer, for example, itis possible to use a straight-chained or branch-chainedalkyl(meth)acrylate, alicyclic(meth)acrylate (an unsaturated bonding maybe included in its ring.), ethylene glycol ester-type (meth)acrylatesuch as hydroxyethyl(meth)acrylate, methoxyethyl(meth)acrylate,propylene glycol-type (meth)acrylate, glycerol mono(meth)acrylate,aromatic-type (meth)acrylate such as benzyl(meth)acrylate,acrylamide-type compound such as (meth)acrylamide,N-methyl(meth)acrylamide, N-propyl(meth)acrylamide anddiacetone(meth)acrylamide, vinyl pyrrolidone, acrylonitrile, vinylacetate, styrene, α-methyl styrene, or vinyl ether.

[0038] As the second ethylenically unsaturated monomer, for example, itis possible to use (meth)acrylic acid, maleic acid, crotonic acid, oritaconic acid.

[0039] As the ethylenically unsaturated compound having the single epoxygroup of the prepolymer (B3), for example, it is possible to use aglycidyl(meth)acrylate such as glycidyl(meth)acrylate and2-methylglycidyl(meth)acrylate, or an epoxy cyclohexyl derivative of a(meth)acrylic acid such as (3,4-epoxy cyclohexyl)methyl(meth) acrylate.

[0040] As the prepolymer (B), for example, it is also possible to use aphotosensitive prepolymer (B4) obtained by a reaction of a polymer or acopolymer containing an ethylenically unsaturated monomer having anepoxy group as polymerization unit with an unsaturated monocarboxylicacid and a saturated or unsaturated polybasic acid anhydride. Theprepolymer (B4) can be prepared by conventional methods.

[0041] As the ethylenically unsaturated monomer having the epoxy groupof the prepolymer (B4), for example, it is possible to use theethylenically unsaturated compound having the single epoxy group of theprepolymer (B3).

[0042] When using the copolymer containing the ethylenically unsaturatedmonomer, it is possible to use an unsaturated monomer polymerizable withthe ethylenically unsaturated monomer having the epoxy group. Forexample, the first ethylenically unsaturated monomer of the loprepolymer (B3) may be used as the unsaturated monomer.

[0043] As the unsaturated monocarboxylic acid and the saturated orunsaturated polybasic acid anhydride of the prepolymer (B4), forexample, it is possible to use those of the prepolymer (B1).

[0044] In addition, as the prepolymer (B), for example, it is possibleto use a photosensitive prepolymer (B5) obtained by a reaction of partsof carboxyl groups in a cellulose derivative having carboxyl groups witha compound having an epoxy group and at least one ethylenicallyunsaturated group.

[0045] For example, the prepolymer (B5) can be prepared by the followingmethod. That is, the compound having the epoxy group and at least oneethylenically unsaturated group is added to a hydrophilic solventsolution of the cellulose derivative in the presence of a polymerizationinhibitor and a catalyst. The resultant is agitated and mixed to obtaina mixture. The mixture is kept at a reaction temperature of 60 to 150°C., and more preferably 80 to 120° C. to obtain the prepolymer (B5). Asthe polymerization inhibitor, it is possible to use hydroquinone orhydroquinone monomethyl ether. As the catalyst, it is possible to use atertiary amine such as benzyl dimethyl amine and triethyl amine, aquaternary ammonium salt such as trimethyl benzyl ammonium chloride andmethyl triethyl ammonium chloride, or triphenyl stibine.

[0046] As the cellulose derivative of the prepolymer (B5), for example,it is possible to use hydroxypropyl methylcellulose phthalate,hydroxypropyl methylcellulose acetate succinate, cellulose acetatehexahydrophthalate, hydroxypropyl methylcellulose acetate phthalate, orhydroxypropyl methylcellulose hexahydrophthalate.

[0047] As the compound having the epoxy group and at least oneethylenically unsaturated group of the prepolymer (B5), for example, itis possible to use a glycidyl(meth)acrylate such as glycidyl(meth)acrylate and 2-methyl glycidyl(meth)acrylate, or an epoxy cyclohexylderivative of a (meth)acrylic acid such as (3,4-epoxy cyclohexyl)methyl(meth)acrylate.

[0048] By the way, when all of the carboxyl groups in the cellulosederivative reacts with epoxy groups, the prepolymer (B5) of the reactionproduct becomes to be insoluble to the diluted alkali aqueous solution.Therefore, an amount used of the compound having the epoxy group and atleast one ethylenically unsaturated group should be determined such thatparts of carboxyl groups of the cellulose derivative remain in theprepolymer (B5).

[0049] In addition, as the prepolymer (B), for example, it is possibleto use a photosensitive prepolymer (B6) obtained by a reaction of acompound having a single epoxy group and at least one ethylenicallyunsaturated group and a saturated or unsaturated polybasic acidanhydride with a cellulose derivative having carboxyl groups.

[0050] For example, the prepolymer (B6) can be prepared by the followingmethod. That is, a reaction product is obtained by a reaction of all orparts of the carboxyl groups of the cellulose derivative with theunsaturated group. Then, the saturated or unsaturated polybasic acidanhydride is added to the reaction product to obtain the prepolymer(B6). As a method of preparing the reaction product, it is possible touse the same method explained for the prepolymer (B5). The additionreaction can be performed according to conventional methods.

[0051] As the cellulose derivative and the compound having the epoxygroup and at least one ethylenically unsaturated group of the prepolymer(B6), for example, it is possible to use those of the prepolymer (B5).As the saturated or unsaturated polybasic acid anhydride of theprepolymer (B6), for example, it is possible to use those of theprepolymer (B 1).

[0052] As the photopolymerization initiator (C), for example, it ispossible to use benzoin, alkyl ether of benzoin such as benzoin methylether, benzoin ethyl ether and benzoin isopropyl ether, acetophenonesuch as acetophenone, 2,2-dimethoxy-2-phenyl acetophenone,2,2-diethoxy-2-phenyl acetophenone, 1,1-dichioro acetophenone, 1-hydroxycyclohexyl phenyl ketone, and4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl) ketone, anthraquinonesuch as 2-methyl anthraquinone and 2-amyl anthraquinone, thioxanthonesuch as 2,4-dimethyl thioxanthone, 2,4-diethy thioxanthone, 2-chlorothioxanthone, 2,4-diisopropyl thioxanthone and 1-chloro-4-propoxythioxanthone, ketal such as acetophenone dimethyl ketal and benzyldimethyl ketal, xanthone, benzophenone such as 3,3-dimethyl-4-methoxybenzophenone, 3,3′,4, 4′-tetra-(tert-butyl peroxyl carbonyl)benzophenone and 4-benzoyl-4′-methyl diphenyl sulfido,nitrogen-containing compound such as2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propane-1-on,2-4′-bis-diethyl amino benzophenone, or 2,4,6-trimethyl benzoyl diphenylphosphine oxide. The photopolymerization initiator can be one of thesematerials, or can be a combination of two or more of these materials, ifnecessary.

[0053] The photopolymerization initiator (C) may be used together with aconventional photopolymerization enhancer or sensitizer such as abenzoic acid, and a tertiary amine, e.g., p-dimethyl amino benzoic acidethyl ester, p-dimethyl amino benzoic acid isoamyl ester, and 2-dimethylamino ethyl benzoate.

[0054] As a first optional component, the photosensitive resincomposition of the present invention can contain a photopolymerizableethylenically unsaturated monomer (E). As the monomer (E), for example,it is possible to use trimethylol propane tri(meth)acrylate,pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate,dipentaerythritol penta(meth)acrylate, dipentaerythritolhexa(meth)acrylate, 1,4-butanediol diacrylate, 1,6-hexane dioldi(meth)acrylate, neopentyl glycol di(meth)acrylate, tripropylene glycoldi(meth)acrylate, 2,2-bis[4-((meth)acryloxy ethoxy) phenyl]propane,2,2-bis[4-((meth)acryloxy diethoxy) phenyl]propane,2-hydroxy-1,3-di(meth)acryloxy propane, ethylene glycoldi(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycoldi(meth)acrylate, phenoxy ethyl(meth)acrylate, phenoxy diethyleneglycol(meth)acrylate, methoxy diethylene glycol(meth)acrylate,tetrahydro furfuryl(meth)acrylate, dicyclopentenyl hydroxyethyl(meth)acrylate, 1-methoxy dodecadienyl(meth)acrylate,β-(meth)acryloyl hydroxy ethyl hydrogen phthalate, β-(meth)acryloylhydroxy ethyl hydrogen succinate, 3-chloro-2-hydroxypropyl(meth)acrylate, lauryl(meth)acrylate, cetyl(meth)acrylate,stearyl(meth)acrylate, bisphenol A-diepoxy acrylic acid adduct,(meth)acrylamide, N-methoxy methyl(meth)acrylamide,N,N-dimethyl(meth)acrylamide, (meth)acryloyl morpholine,N-methylol(meth) acrylamide, hydroxy propyl(meth)acrylate, polyethyleneglycol di (meth)acrylate, methylene bis(meth)acrylamide, 2-hydroxy ethyl(meth)acrylate,2,2-bis[4-methacryloyl hydroxy polyethoxy phenyl]propane.The monomer (E) can be one of these materials or can be a combination oftwo or more of these materials, if necessary.

[0055] As a second optional component, the photosensitive resincomposition of the present invention can contain an organic solvent. Anamount used of the organic solvent should be determined such that theproblems inherent in the use of the organic solvent are ignorable. Forexample, as the organic solvent, it is possible to use an alcohol suchas ethanol, propanol, 2-propanol, butanol, 2-butanol, hexanol, ethyleneglycol, diethylene glycol, triethylene glycol, propylene glycol,dipropylene glycol, butylene glycol, trimethylol propane, neopentylglycol, glycerin, 1,2,4-butanetriol, 1,2-butanediol, 1,4-butanediol anddiacetone alcohol, ethylene glycol alkyl ether such as ethylene glycolmonomethyl ether, ethylene glycol monoethyl ether and ethylene glycolmonobutyl ether, polyethylene glycol alkyl ether such as diethyleneglycol monomethyl ether, diethylene glycol monocthyl ether andtriethylene glycol monomethyl ether, propylene glycol alkyl ether suchas propylene glycol monomethyl ether, polypropylene glycol alkyl ethersuch as dipropylene glycol monomethyl ether, acetic ester such asethylene glycol monomethyl ether acetate, diethylene glycol monomethylether acetate, propylene glycol monomethyl ether acetate, dipropyleneglycol monomethyl ether acetate, glycerin monoacetate and glycerindiacetate, lactic ester such as lactic ethyl and lactic butyl, dialkylglycol ether such as diethylene glycol diethyl ether, ketone such asmethyl ethyl ketone, cyclohexanone and isophorone, aromatic hydrocarbonsuch as toluene and xylene, oil and aromatic-type mixed solvent such as“SWASOL SERIES” (manufactured by Maruzen Petrochemical Co., Ltd.) and“SOLVESSO SERIES” (manufactured by EXXON CHEMICAL COMPANY), n-hexane,cyclohexane, or tetrahydrofuran. The organic solvent can be one of thesematerials, or can be a combination of two or more of these materials, ifnecessary.

[0056] The photosensitive resin composition of the present invention mayalso contain a leveling agent such as a fluorine surface active agent,silicone and a (meth)acrylate copolymer, a thixotropic agent such asAEROSIL, a polymerization inhibitor such as hydroquinone, hydroquinonemonomethyl ether, pyrogallol, tert-butyl catechol and phenothiazine,antihalation agent, flame retardant, plating-resistance improving agent,defoamer, anti-oxidant, pigment wetting agent, organic or inorganicpigment and dye, additives such as synthetic rubber powder and naturalrubber powder, high molecular dispersing agent or surface-active agentfor improving the dispersion stability.

[0057] It is preferred to prepare the photosensitive resin compositionof the present invention according to the following compounding amountsof the water-soluble photosensitive resin (A), photosensitive prepolymer(B), photopolymerization initiator (C) and water (D).

[0058] That is, it is preferred that the compounding amount of thewater-soluble photosensitive resin (A) is 0.1 to 50 wt %, and morepreferably 1 to 30 wt % with respect to the total amount of allcomponents of the solvent as the second optional component. In the aboverange, there are advantages that (1) the photosensitive resincomposition is excellent in the water-solubility; (2) a cured film ofthe photosensitive resin composition exhibits good water resistance; and(3) a peeling of the cured film is hardly generated at the time of theformation of the cured film. In particular, when the compounding amountis 0.5 to 50 wt %, the photosensitive resin composition can be easilydeveloped with water.

[0059] It is preferred that the compounding amount of the photosensitiveprepolymer (B) is 30 wt % or more with respect to the total amount ofall components of the photosensitive resin composition except for water(D) and the organic solvent as the second optional component. In theabove range, there is an advantage that a predried film of thephotosensitive resin composition is almost free from the surfacetackiness.

[0060] It is preferred that the compounding amount of thephotopolymerization initiator (C) is within a range of 0.1 to 20 wt %with respect to the total amount of all components of the photosensitiveresin composition except for water (D) and the organic solvent as thesecond optional component. In the above range, there is an advantagethat the photosensitive resin composition is excellent in thephoto-curability.

[0061] It is preferred that the compounding amount of water (D) iswithin a range of 10 to 97 wt % with respect to the total amount of allcomponents of the photosensitive resin composition. In the above range,there is an advantage that the fluidity of the photosensitive resincomposition is suitable to uniformly apply the resin composition onsubstrates. ethylenically unsaturated monomer (E), it is preferred thatthe compounding amount of the monomer (E) is 75 wt % or less withrespect to the total amount of all components of the photosensitiveresin composition except for water (D) and the organic solvent as thesecond optional component. The monomer (E) is useful to more improve thephotoreactivity of the photosensitive resin composition. When thecompounding amount is more than 75 wt %, there is a possibility that thesurface tackiness of the predried film of the photosensitive resincomposition comes into problem.

[0062] There is no limitation as to a method of preparing thephotosensitive resin composition of the present invention. For example,the components (A) to (C) and the other optional components may bedissolved, emulsified, and dispersed in water (D) or a mixture of waterand an aqueous organic solvent to obtain the photosensitive resincomposition. Alternatively, an aqueous solution of the component (A) maybe added to the components (B) and (C) and the other optionalcomponents, and ten mixed to obtain the photosensitive resincomposition. In these methods, it is preferred to use an agitator or amuller such as homomixer, pipeline homomixer, bead mill, roll mill andball mill.

[0063] Next, a method of forming a required pattern on a substrate withthe use of the photosensitive resin composition of the present inventionis explained as an example.

[0064] <Applying Step>

[0065] First, the photosensitive resin composition can be applied on asubstrate by a dipping method, spray method, spin-coating method, rollmethod. A copper clad laminate used to manufacture printed wiring boardsmay be used as the substrate.

[0066] <Predrying Step>

[0067] The photosensitive resin composition on the substrate can bedried by a hot-air drying method, electromagnetic induction heating,hot-pressing, or a far-infrared drying method to obtain a predried film.

[0068] <Exposing Step>

[0069] After a mask having a required pattern such as a phototoolartwork is directly or indirectly put on the predried film, ultravioletcan be radiated to the predried film through the mask by using atungsten lamp, chemical lamp, low-pressure mercury lamp, medium-pressuremercury lamp, high-pressure mercury lamp, extra-high-pressure mercurylamp, xenon lamp or a metalhalide lamp. Alternatively, it is preferredto adopt a laser patterning method using a helium-cadmium laser, argonlaser or a YAG laser.

[0070] <Developing Step>

[0071] After the exposing step, the predried film can be developed withwater or a diluted alkali aqueous solution, so that the non-exposedregion of the predried film is washed away to leave the exposed regionof the predried film on the substrate as a resist pattern. Whendeveloping with the diluted alkali aqueous solution, it is preferred touse an aqueous solution of an alkali hydroxide such as sodium hydroxide,potassium hydroxide and lithium hydroxide, or an alkali carbonate suchas sodium carbonate and potassium carbonate.

[0072] <Etching or Plating Step>

[0073] The etching or plating step can be performed to the substrateWhen performing the etching step, it is preferred to select an etchingagent in accordance with a material of a conductive layer of thesubstrate. For example, an acid etching solution such as copper (II)chloride, or an ammonia etching solution may be used. When performingthe plating step, it is possible to perform a copper plating such as acopper-sulfate plating and a copper pyrophosphate plating, solderplating such as a high throw solder plating, nickel plating such as anickel sulfamate plating, or a gold plating such as a soft gold platingand a hard gold plating.

[0074] <Removing Step of Resist Pattern>

[0075] When it is required to strip and remove the resist pattern fromthe substrate, the resist pattern can be readily stripped and removedwith the use of sodium periodate or sodium hypochlorite. Alternatively,it is possible to remove the resist film from the substrate with the useof a stronger alkali aqueous solution than the alkali aqueous solutionused at the developing step.

[0076] Consequently, the photosensitive resin composition of the presentinvention can provide the following advantages.

[0077] (1) Since the photosensitive resin composition does notessentially contain the organic solvent, it is possible to prevent theoccurrence of the problems inherent in the use of the organic solvent.

[0078] (2) A predried film of the photosensitive resin composition canbe developed with water or a diluted alkali aqueous solution.

[0079] (3) A film of the photosensitive resin composition cured by thephotopolymerization reaction is excellent in film hardness, resistanceto etching solution, resistance to plating solution, and thermalresistance. In addition, the cured film has good adhesion with thesubstrate.

[0080] (4) The cured film of the photosensitive resin composition can beremoved from the substrate with the use of sodium periodate or anaqueous solution of an alkali-metal hydroxide.

[0081] Therefore, the photosensitive resin composition of the presentinvention will be preferably used as a photoresist ink for manufacturingprinted wiring boards such as an etching resist ink, plating resist ink,solder resist ink and marking ink, photoresist ink for photogravure,photosensitive composition for manufacturing screen printing stencils,ink for manufacturing color-filter pixels, or an ink for manufacturingcolor-filter protective films.

EXAMPLES AND COMPARATIVE EXAMPLES

[0082] The followings are preferred examples of the present invention.However, needless to say, the present invention is not limited to theseexamples. The units “parts” and “%” used in the examples means “parts byweight” and “wt %”, respectively. In addition, “weight-average molecularweight” was measured by a GPC (Gel Permeation Chromatography) methodunder the following condition.

[0083] [GPC Measuring Condition]

[0084] GPC Measuring Apparatus:

[0085] SHODEX SYSTEM 11 manufactured by Showa Denko K. K.

[0086] Column: SHODEX KF-800P, KF-805, KF-803 and KF-801 in series

[0087] Transfer Layer: THF (Tetrahydrofuran)

[0088] Flow Rate: 1 ml/min.

[0089] Column Temperature: 45° C.

[0090] Detector: RI

[0091] Conversion: Polystyrene

[0092] In the GPC measurement, a THF (tetrahydrofuran) solution having aconcentration of 10 mg/ml with respect to a solid part of each samplewas prepared, and the injection amount is 100 μl.

[0093] [Preparation of Photosensitive Resin Aqueous Solution (S-1)]

[0094] 200 g of a partially-saponified polyvinyl acetate “GOHSENOLGH-17” (manufactured by The Nippon Synthetic Chemical Industry Co.,Ltd., Degree of polymerization: 1700, Degree of saponification: 88 mol%) was dissolved in 1774 g of water to obtain a first mixture. After 20g of N-methyl-4-(p-formyl styryl) pyridinium methosulfate was added tothe first mixture to obtain a second mixture, 6 g of an 85% phosphoricacid aqueous solution was added to the second mixture to obtain a thirdmixture. The third mixture was kept at 80° C. for 7 hours to obtain thephotosensitive resin aqueous solution (S-1), which corresponds to anaqueous solution of the water-soluble photosensitive resin (A1).

[0095] [Preparation of Photosensitive Resin Aqueous Solution (S-2)]

[0096] 200 g of a partially-saponified polyvinyl acetate “PVA-224”(manufactured by Kuraray Co., Ltd., Degree of polymerization: 2400,Degree of saponification: 88 mol %) was dissolved in 1774 g of water toobtain a first mixture. After 20 g of N-methyl-4-(p-formyl styryl)quinolinium methosulfate was added to the first mixture to obtain asecond mixture, 6 g of an 85% phosphoric acid aqueous solution was addedto the second mixture to obtain a third mixture. The third mixture waskept at 70° C. for 5 hours to obtain the photosensitive resin aqueoussolution (S-2), which corresponds to an aqueous solution of thewater-soluble photosensitive resin (A1).

[0097] [Preparation of Photosensitive Resin Aqueous Solution (S-3)]

[0098] 200 g of a partially-saponified polyvinyl acetate “GOHSENOLGH-17” (manufactured by The Nippon Synthetic Chemical Industry Co.,Ltd., Degree of polymerization: 1700, Degree of saponification: 88 mol%) was dissolved in 1000 g of water to obtain a first mixture. 40 g ofN-methylol acrylamide was dissolved in the first mixture to obtain asecond mixture, and then 2 g of a 0.1% methoxy hydroquinone aqueoussolution and 3 g of an 85% phosphoric acid aqueous solution were addedto the second mixture to obtain a third mixture. After the third mixturewas kept at 60° C. for 20 hours, the third mixture was neutralized witha 5% caustic soda aqueous solution to obtain a fourth mixture. Water wasalso added to the fourth mixture such that its total weight is 1500 g,to thereby obtain the photosensitive resin aqueous solution (S-3), whichcorresponds to an aqueous solution of the water-soluble photosensitiveresin (A2).

[0099] [Preparation of Photosensitive Resin Aqueous Solution (S-4)]

[0100] 200 g of a partially saponified of a vinyl acetatepolymer-unsaturated carboxylic acid Na copolymer “KL318” (manufacturedby Kuraray Co., Ltd., Degree of polymerization: 1800, Degree ofsaponification: 88 mol %) was dissolved in 1000 g of water to obtain afirst mixture. 60 g of N-methylol acrylamide was dissolved in the firstmixture to obtain a second mixture, and then 2 g of a 0.1% methoxyhydroquinone aqueous solution and 3 g of an 85% phosphoric acid aqueoussolution were added to the second mixture to obtain a third mixture.After the third mixture was kept at 80° C. for 5 hours, the thirdmixture was neutralized with a 5% caustic soda aqueous solution toobtain a fourth mixture. Water was also added to the fourth mixture suchthat its total weight is 1625 g to obtain the photosensitive resinaqueous solution (S-4), which corresponds to an aqueous solution of thewater-soluble photosensitive resin (A2).

[0101] [Preparation of Photosensitive Prepolymer Solution (P-1)]

[0102] 214 parts of a cresol novolac-type epoxy resin “EPICLON N-680”(manufactured by DAINIPPON INK AND CHEMICALS INCORPORATED, EpoxyEquivalents: 214) was dissolved in 60 parts of methyl ethyl ketone at araised temperature under an airflow to obtain a first mixture. Next, 74parts of acrylic acid, 0.1 parts of hydroquinone, and 2.0 parts ofdimethyl benzylamine were added to the first mixture to obtain a secondmixture. The second mixture was held at 80° C. for 24 hours to obtain athird mixture. After the third mixture was cooled, 136 parts of methylethyl ketone and 76 parts of tetrahydro phthalic anhydride were added tothe third mixture to obtain a fourth mixture. The fourth mixture waskept at 80° C. for 10 hours while being agitated, to obtain a 65%photosensitive prepolymer solution (P-1), which corresponds to asolution of the photosensitive prepolymer (B1). The weight-averagemolecular weight and the acid value of the prepolymer solution (P-1) are12000 and 77 mgKOH/g, respectively.

[0103] [Preparation of Photosensitive Prepolymer Solution (P-2)]

[0104] 150 parts of a styrene-maleic anhydride copolymer “SMA-1000A”(manufactured by ELF ATOCHEM JAPAN, INC.) was dissolved in 149 parts ofmethyl ethyl ketone at a raised temperature under an airflow to obtain afirst mixture. Next, 51 parts of 2-hydroxy ethyl acrylate, 0.1 parts ofhydroquinone, and 3 part of dimethyl benzylamine were added to the firstmixture to obtain a second mixture. After the second mixture was held at80° C. for 12 hours to obtain a third mixture. 22 parts of n-butanol wasadded to the third mixture, and then held for 24 hours to obtain a 60%photosensitive prepolymer solution (P-2), which corresponds to asolution of the photosensitive prepolymer (B2). The weight-averagemolecular weight and the acid value of the prepolymer solution (P-2) are7500 and 156 mgKOH/g, respectively.

[0105] [Preparation of photosensitive prepolymer solution (P-3)]

[0106] 20 parts of methacrylic acid, 80 parts of methyl methacrylate,100 parts of methyl ethyl ketone, 0.5 parts of lauryl mercaptan and 4parts of azobis isobutyronitrile were put in a four-mouth flask, andheld at 75° C. for 5 hours at a raised temperature under a nitrogen flowto obtain a 50% copolymer solution. The four-mouth flask has athermometer, glass tube for nitrogen substitution, agitator, and areflux condenser. Next, 15 parts of glycidyl methacrylate, 0.05 parts ofhydroquinone and 2.0 parts of dimethyl benzylamine were added to thecopolymer solution, and held at 80° C. for 24 hours under an air flow.Then, 13 parts of methyl ethyl ketone were added to the resultant toobtain a 50% photosensitive prepolymer solution (P-3), which correspondsto a solution of the photosensitive prepolymer (B3). The weight-averagemolecular weight and the acid value of the prepolymer solution (P-3) are15000 and 62 mgKOH/g, respectively.

[0107] [(Preparation of Photosensitive Prepolymer Solution (P-4)]

[0108] 70 parts of glycidyl methacrylate, 10 parts of methylmethacrylate, 20 parts of tert-butyl methacrylate, 100 parts of methylethyl ketone, 0.5 parts of lauryl mercaptan and 3 parts of azobisisobutyronitrile were put in a four-mouth flask, and held at 75° C. for5 hours at a raised temperature under a nitrogen flow to obtain a 50%copolymer solution. The four-mouth flask has a thermometer, glass tubefor nitrogen substitution, agitator, and a reflux condenser. Next, 0.05parts of hydroquinone, 37 parts of acrylic and 2.0 parts of dimethylbenzylamine were added to the copolymer solution, and held at 80° C. for24 hours under an air flow. Then, 38 parts of tetrahydrophthalicanhydride and 73 parts of methyl ethyl ketone were added to theresultant, and held at 80° C. for 10 hours to obtain a 50%photosensitive prepolymer solution (P-4), which corresponds to asolution of the photosensitive prepolymer (B4). The weight-averagemolecular weight and the acid value of the prepolymer solution (P-4) are22000 and 80 mgKOH/g, respectively.

[0109] [Preparation of Photosensitive Prepolymer Solution (P-5)]

[0110] 30 parts of hydroxypropyl methylcellulose acetate succinate“AS-L” (manufactured by Shin-Etsu Chemical Co., Ltd.), 80 parts ofmethyl ethyl ketone, 0.05 parts of hydroquinone, 2.6 parts of glycidylmethacrylate and 2.0 parts of dimethyl benzylamine were put in afour-mouth flask, and held at 80° C. for 24 hours. The four-mouth flaskhas a thermometer, agitator, and a reflux condenser. Next, 8.4 parts ofmethyl ethyl ketone were added to the resultant to obtain a 28%photosensitive prepolymer solution (P-5), which corresponds to asolution of the photosensitive prepolymer (B5). The weight-averagemolecular weight and the acid value of the prepolymer solution (P-5) are63500 and 47.5 mgKOH/g, respectively.

[0111] [Preparation of Photosensitive Prepolymer Solution (P-6)]

[0112] 40 parts of hydroxypropyl methylcellulose acetate succinate“AS-L” (manufactured by Shin-Etsu Chemical Co., Ltd.), 100 parts ofmethyl ethyl ketone, 0.05 parts of hydroquinone, 8.7 parts of glycidylmethacrylate and 2.0 parts of dimethyl benzylamine were put in afour-mouth flask, and held at 80° C. for 24 hours. The four-mouth flaskhas a thermometer, agitator, and a reflux condenser. Next, 9.3 parts oftetrahydrophthalic anhydride and 5.7 parts of methyl ethyl ketone wereadded to the resultant, and held at 80° C. for 10 hours to obtain a 35%photosensitive prepolymer solution (P-6), which corresponds to asolution of the photosensitive prepolymer (B6). The weight-averagemolecular weight and the acid value of the prepolymer solution (P-6) are200000 and 59 mgKOH/g, respectively.

[0113] [Preparation of Photosensitive Prepolymer Solution (Q-1)]

[0114] 150 parts of a styrene-maleic anhydride copolymer “SMA-1000A”(manufactured by ELF ATOCHEM JAPAN, INC.) was dissolved in 149 parts ofpropylene glycol monomethyl ether acetate at a raised temperature toobtain a first mixture. Next, 51 parts of 2-hydroxyethyl acrylate, 0.1parts of hydroquinone, and 3.0 parts of dimethyl benzylamine were addedto the first mixture under an air flow, and held at 80° C. for 12 hoursto obtain a second mixture. 22 parts of n-butanol was added to thesecond mixture, and held for 24 hours to obtain a 60% photosensitiveprepolymer solution (Q-1) for Comparative Example 1. The weight-averagemolecular weight and the acid value of the prepolymer solution (Q-1) are7500 and 156 mgKOH/g, respectively.

[0115] [Preparation of Photosensitive Prepolymer Solution (Q-2)]

[0116] 20 parts of methacrylic acid, 80 parts of methyl methacrylate,100 parts of propylene glycol monomethyl ether acetate, 0.5 parts oflauryl mercaptan and 2 parts of azobis dimethyl valeronitrile were putin a four-mouth flask, and held at 110° C. for 5 hours under a nitrogenflow to obtain a 50% copolymer solution. The four-mouth flask has athermometer, glass tube for nitrogen substitution, agitator, and areflux condenser. Next, 15 parts of glycidyl methacrylate, 0.05 parts ofhydroquinone and 2.0 parts of dimethyl benzylamine were added to thecopolymer solution, and held at 80° C. for 24 hours under an air flow.Then, 11 parts of propylene glycol monomethyl ether acetate were addedto the resultant to obtain a 50% photosensitive prepolymer solution(Q-2) for Comparative Example 2. The weight-average molecular weight andthe acid value of the prepolymer solution (Q-2) are 18000 and 62mgKOH/g, respectively.

Examples 1 to 30

[0117] Each of the photosensitive resin compositions of Examples 1 to 30was prepared according to the following method. That is, a mixtureprepared according to compounding amounts listed in Tables 1 to 3 wassufficiently agitated by a homomixer, and then heated at 65° C. under anair flow to remove an organic solvent component therefrom, to therebyobtain the photosensitive resin composition of the present invention.

Comparative Examples 1 and 2

[0118] Each of photosensitive resin compositions of Comparative Examples1 and 2 was prepared by mixing the photosensitive prepolymer solution(Q-1) or (Q-2) with the other components according to compoundingamounts listed in Table 3, while agitating the resultant.

[0119] In Tables 1 to 3, trimethylol propane triacrylate (*1) is “ARONIXM-309” manufactured by Toagosei Co., Ltd. The Phenol denaturedmonofunctional acrylate (*2) is “ARONIX M-101” manufactured by ToagoseiCo., Ltd. The photopolymerization initiator (*3) is “Irgacure 907”manufactured by CIBA-GEIGY CORPORATION. The photopolymerizationinitiator (*4) is “KAYACURE DETX” manufactured by Nippon Kayaku Co.,Ltd. The organic dye (*5) is “VICTORIA PURE BLUE BOH” manufactured byHodogaya Chemical Co., Ltd.

[0120] With respect to Examples 1-30 and Comparative Examples 1 and 2,the following evaluations were performed. Results are shown in Tables 4to 7.

[0121] [1] Thickness of Predried Film

[0122] The photosensitive resin composition was applied on both surfacesof an FR-4 double-sided copper clad laminate as a substrate by the useof a vertical roll coater. The clad laminate has a substrate thicknessof 1.6 mm and a copper-foil thickness of 35 μm as a conductive layer.After the clad laminate with the photosensitive resin composition wasdried at 80° C. for 15 minutes under a hot-air convention, it was cooledat a room temperature to obtain predried films on the clad laminate. Thethickness of the predried film was measured.

[0123] [2] Surface Tackiness of Predried Film

[0124] A pair of phototool artworks having wiring patterns were directlyput on the predried films. The predried films were simultaneouslyexposed through the phototool artworks by the use of anextra-high-pressure mercury lamp such that the accumulated light-amountis 200 mJ/cm². After the exposing step, the surface tackiness of thepredried film was evaluated by removing the phototool artworks from thepredried films. In Tables 4 to 7, the word “Good” used to show a degreeof the surface tackiness designates that the phototool artwork waseasily removed from the predried film without contamination of thephototool artwork with the photosensitive resin composition.

[0125] [3] Developing Property

[0126] The developing property of the predried film was evaluated underthe following conditions (i) and (ii).

[0127] (i) After the exposing step, the predried film was developed byspraying a 1 wt % sodium carbonate aqueous solution thereto at 30° C. ata spray pressure of 1. 5 Kg/cm² for 1 minute, so that the non-exposedportion of the predried film was removed.

[0128] (ii) After the exposing step, the predried film was developed byspraying water thereto at 30° C. at a spray pressure of 1. 5 Kg/cm² for3 minutes, so that the non-exposed portion of the predried film wasremoved.

[0129] In Tables 4 to 7, the symbol “⊚” designates that the non-exposedportion of the predried film was completely removed. The symbol “◯”designates that most of the non-exposed portion of the predried film wasremoved, but a part of the non-exposed portion remained at the boundarybetween the non-exposed portion and the exposed portion. The symbol “X”designates that the non-exposed portion of the predried film could notbe removed.

[0130] [4] Adhesion Test (1)

[0131] After the exposing and developing step, the adhesion of a curedfilm (=the exposed portion of the predried film) of the photosensitiveresin composition was evaluated. The adhesion test was performedaccording to Japanese Industrial Standard D 0202-1988, 4.15. In thisadhesion test, 100 square cuts were formed in the cured film to obtain100 square blocks, and then an adhesion tape was put on the 100 squareblocks of the cured film. After the adhesion tape was peeled off fromthe cured film, the number of the remaining blocks of the cured film onthe substrate was counted. The adhesion of the cured film was evaluatedby a ratio of the number (N) of the remaining blocks to 100 blocks ofthe cured film. In Tables 4 to 7, the numeral “1” used to show a degreeof the adhesion of the cured film designates that the number (N) of theremaining blocks is 100.

[0132] [5] Resistance to Etching Solution

[0133] The resistance to etching solution means the resistance to anacid aqueous solution of the cured film. After the developing step, anetching treatment of the conductive layer on the substrate with thecured film as a mask was performed with a 40 wt % iron (III) chlorideaqueous solution at 45° C. for 240 seconds to obtain a conductivepattern on the substrate. In Tables 4 to 7, the word “good” used to showa degree of the resistance to etching solution designates that there isno occurrence of peeling of the cured film during the etching treatment

[0134] [6] Removing Test of Cured Film

[0135] With respect to the Examples 1 to 6, 13 to 18, 25, 27, 29, 30 andComparative Examples 1 and 2, the cured film was stripped and removed byspraying a 3% sodium hydroxide aqueous solution thereto at 45° C. at aspray pressure of 2 kg/ cm². On the other hand, with respect to theExamples 7 to 12, 19 to 24, 26, 28 and Comparative Examples 1 and 2, thecured film was stripped and removed by dipping the cured film in a 3%periodic acid aqueous solution at 20° C. for 2 minutes and spraying theaqueous solution thereto at a spray pressure of 2 kg/cm². To evaluatethe removing easiness of the cured film, time required to completelystrip and remove the cured film was measured, as shown in Tables 4 to 7.In Table 7, the symbol “X” designates that the cured film could not beremoved.

[0136] [7] Etching Property

[0137] After the cured film was stripped and removed, defects of theconductive pattern such as faults, a decrease in line width, pinhole,and a poor linearity of pattern were checked. In Tables 4 to 7, the word“good” used to show the etching property designates that there is nooccurrence of such defects of the conductive pattern.

[0138] [8] Plating Resistance

[0139] After the developing step, the cured film was dipped in a 25 wt %aqueous solution of an agent “PC-455” (manufactured by Meltex Inc.) at30° C. for 5 minutes for the purpose of degrease. Then, the cured filmwas washed with water, and was dipped in a 20 wt % aqueous solution ofan ammonium persulfate-type soft etching agent “NPE-300” (manufacturedby Mitsubishi Gas Chemical Co., Ltd.) at a room temperature for 2minutes. In addition, the cured film was washed with water, and then itwas dipped in a 10 wt % sulfuric acid aqueous solution at a roomtemperature for 1 minute. Next, the cured film was put in a nickelplating bath containing 300 g of nickel sulfate, 40 g of nickelchloride, 40 g of boric acid and 620 g of water, and a nickel platingwas performed at 45° C. at 1.5 A/dm for 10 minutes. After the nickelplating, water washing was performed. Continuously, a gold plating wasperformed in a gold plating bath of “OROBRIGHT HS-2” (manufactured byJAPAN PURE CHEMICAL CO., LTD) at 40° C. at 1.0 A/dm for 10 minutes. InTables 4 to 7, the word “good” used to show a degree of the resistanceto plating solution designates that there is no occurrence of flaking ofthe cured film during the plating procedure.

[0140] [9] Adhesion Test (II)

[0141] After the plating procedure of the item [8], the cured film waswashed by water and then dried. The adhesion of the cured film wasevaluated according to Japanese Industrial Standard D 0202-1988, 4.15.The brief explanation of this adhesion test was already described in theitem [4]. Results are shown in Tables 4 to 7.

[0142] [10] Plating Property

[0143] After the plating procedure of the item [8], the cured film wasstripped and removed from the substrate by spraying a 3% sodiumhydroxide aqueous solution thereto at 45° C. at a spray pressure of 2kg/cm². Then, the occurrence of plating defects was checked by the useof a magnifying glass. In Tables 4 to 7, the word “good” used to showthe plating property designates that there is no occurrence of platingdefects.

[0144] [11] Evaluation of Conductive Pattern

[0145] After the cured-film removing step of the item [10], an alkalietching treatment was performed. The linearity of a line pattern of thegold plating was checked by the use of an optical microscope. Withrespect to all of Examples and Comparative Examples, a distance betweenthe top of a convex portion and the bottom of a concave portion of thegold line pattern is 1 μm or less.

[0146] As understood from Tables 4 to 7, the photosensitive resincompositions of the Comparative Examples 1 and 2 can be developed with adiluted alkali aqueous solution, but can not be developed with water. Onthe contrary, the photosensitive resin compositions of the Examples 1 to30 can be developed with water as well as the diluted alkali aqueoussolution. In addition, the cured film of the photosensitive resincomposition of each of the Comparative Examples 1 and 2 can not bestripped and removed from the substrate with the sodium periodateaqueous solution. However, the photosensitive resin compositions of allof Examples of the present invention can be stripped and removed withthe sodium periodate aqueous solution as well as the alkali aqueoussolution. The other properties of the photosensitive resin compositionsof Examples 1 to 30 are substantially the same as those of theComparative Examples 1 and 2.

[0147] In addition, it is confirmed that when the sodium carbonateaqueous solution is used as the developer, the developing property ofthe photosensitive resin composition of each of the Examples 1 to 24,which contains trimethyl propane triacrylate or phenol denaturedmonofunctional acrylate as the photopolymerizable ethylenicallyunsaturated monomer (E) is better than that of each of the Examples 25to 30, which does not contain the ethylenically unsaturated monomer (E).

[0148] From these results, the photosensitive resin composition of thepresent invention will be preferably used as an etching resist ink,plating resist ink, solder resist ink or a marking ink. TABLE 1 ExamplesUnit: parts by weight 1 2 3 4 5 6 7 8 9 10 11 Photosensitive resinaqueous solution (S-1) 350 350 350 350 350 350 — — — — — Photosensitiveresin aqueous solution (S-2) — — — — — — 350 350 350 350 350Photosensitive resin aqueous solution (S-3) — — — — — — — — — — —Photosensitive resin aqueous solution (S-4) — — — — — — — — — — — 65%prepolymer solution P-1 370 — — — — — 370 — — — — 60% prepolymersolution P-2 — 420 — — — — — 420 — — — 50% prepolymer solution P-3 — —480 — — — — — 480 — — 50% prepolymer solution P-4 — — — 480 — — — — —480 — 28% prepolymer solution P-5 — — — — 685 — — — — — 685 35%prepolymer solution P-6 — — — — — 685 — — — — — 60% prepolymer solutionQ-1 — — — — — — — — — — — 50% prepolymer solution Q-2 — — — — — — — — —— — Trimethylol propane triacrylate(*1) 50 50 50 50 50 50 50 50 50 50 50Phenol denatured monofunctional acrylate(*2) 40 40 40 40 40 40 40 40 4040 40 Photopolymerization initiator(*3) 30 30 30 30 30 30 30 30 30 30 30Photopolymerization initiator(*4) 5 5 5 5 5 5 5 5 5 5 5 Organic dye*5 55 5 5 5 5 5 5 5 5 5 Hydroquinone 2 2 2 2 2 2 2 2 2 2 2 Dicyandiamide 0.50.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5

[0149] TABLE 2 Examples Unit: parts by weight 12 13 14 15 16 17 18 19 2021 22 Photosensitive resin aqueous solution (S-1) — — — — — — — — — — —Photosensitive resin aqueous solution (S-2) 350 — — — — — — — — — —Photosensitive resin aqueous solution (S-3) 250 250 250 250 250 250 — —— — Photosensitive resin aqueous solution (S-4) — — — — — — — 230 230230 230 65% prepolymer solution (P-1) — 370 — — — — — 370 — — — 60%prepolymer solution (P-2) — — 420 — — — — — 420 — — 50% prepolymersolution (P-3) — — — 480 — — — — — 480 — 50% prepolymer solution (P-4) —— — — 480 — — — — — 480 28% prepolymer solution (P-5) — — — — — 685 — —— — — 35% prepolymer solution (P-6) 685 — — — — 685 — — — — 60%prepolymer solution (Q-1) — — — — — — — — — — — 50% prepolymer solution(Q-2) — — — — — — — — — — — Trimethylol propane triacrylate(*1) 50 50 5050 50 50 50 50 50 50 50 Phenol denatured monofunctional acrylate(*2) 4040 40 40 40 40 40 40 40 40 40 Photopolymerization initiator(*3) 30 30 3030 30 30 30 30 30 30 30 Photopolymerization initiator(*4) 5 5 5 5 5 5 55 5 5 5 Organic dye(*5) 5 5 5 5 5 5 5 5 5 5 5 Hydroquinone 2 2 2 2 2 2 22 2 2 2 Dicyandiamide 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5

[0150] TABLE 3 Comparative Examples Examples Unit: parts by weight 23 2425 26 27 28 29 30 1 2 Photosensitive resin aqueous solution (S-1) — —350 — — — 350 350 — — Photosensitive resin aqueous solution (S-2) — — —350 — — — — — — Photosensitive resin aqueous solution (S-3) — — — — 250— — — — — Photosensitive resin aqueous solution (S-4) 230 230 — — — 230— — — — 65% prepolymer solution (P-1) — — 500 — — — — — — 60% prepolymersolution (P-2) — — — 560 — — — — — — 50% prepolymer solution (P-3) — — —— 640 — — — — — 50% prepolymer solution (P-4) — — — — — 640 — — — — 28%prepolymer solution (P-5) 685 — — — — — 900 — — — 35% prepolymersolution (P-6) — 685 — — — — — 900 — — 60% prepolymer solution (Q-1) — —— — — — — — 490 — 50% prepolymer solution (Q-2) — — — — — — — — — 500Trimethylol propane triacrylate(*1) 50 50 — — — — — — 50 50 Phenoldenatured monofunctional acrylate(*2) 40 40 — — — — — — 40 40Photopolymerization initiator(*3) 30 30 30 30 30 30 30 30 30 30Photopolymerization initiator(*4) 5 5 5 5 5 5 5 5 5 5 Organic dye(*5) 55 5 5 5 5 5 5 5 5 Hydroquinone 2 2 2 2 2 2 2 2 2 2 Dicyandiamide 0.5 0.50.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5

[0151] TABLE 4 Examples 1 2 3 4 5 6 7 8 Exposing/Developing StepThickness of Predried Film (μm)  15  15  15  15  17  17  16  16 SurfaceTackiness of Predried Film Good Good Good Good Good Good Good GoodDeveloping Property (i) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ (ii) ⊚ ⊚ ⊚ ⊚ ⊚ ◯ ⊚ ⊚ AdhesionTest (I) (N/100) 100 100 100 100 100 100 100 100 Etching Step Resistanceto Etching Solution Good Good Good Good Good Good Good Good RemovingTest of Cured Film (unit: second) (I)  15  10  17  20  30  25 — — (ii) —— — — — — 140 100 Etching Property Good Good Good Good Good Good GoodGood Plating Step Plating Resistance Good Good Good Good Good Good GoodGood Adhesion Test (II) (N/100) 100 100 100 100 100 100 100 100 PlatingProperty Good Good Good Good Good Good Good Good Evaluation ofConductive Pattern (μm)  ≦1  ≦1  ≦1  ≦1  ≦1  ≦1  ≦1 ≦1

[0152] TABLE 5 Examples 9 10 11 12 13 14 15 16 Exposing/Developing StepThickness of Predried Film (μm)  16  16  18  18  15  15  15  15 SurfaceTackiness of Predried Film Good Good Good Good Good Good Good GoodDeveloping Property (i) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ (ii) ⊚ ⊚ ⊚ ◯ ⊚ ⊚ ⊚ ⊚ AdhesionTest (I) (N/100) 100 100 100 100 100 100 100 100 Etching Step Resistanceto Etching Solution Good Good Good Good Good Good Good Good RemovingTest of Cured Film (unit: second) (I) — — — —  15  10  17  20 (ii) 160180 250 200 — — — — Etching Property Good Good Good Good Good Good GoodGood Plating Step Plating Resistance Good Good Good Good Good Good GoodGood Adhesion Test (II) (N/100) 100 100 100 100 100 100 100 100 PlatingProperty Good Good Good Good Good Good Good Good Evaluation ofConductive Pattern (μm)  ≦1  ≦1  ≦1  ≦1  ≦1  ≦1  ≦1 ≦1

[0153] TABLE 6 Examples 17 18 19 20 21 22 23 24 Exposing/Developing StepThickness of Predried Film (μm)  17  17  15  15  15  15  17  17 SurfaceTackiness of Predried Film Good Good Good Good Good Good Good GoodDeveloping Property (i) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ (ii) ⊚ ◯ ⊚ ⊚ ⊚ ⊚ ⊚ ◯ AdhesionTest (I) (N/100) 100 100 100 100 100 100 100 100 Etching Step Resistanceto Etching Solution Good Good Good Good Good Good Good Good RemovingTest of Cured Film (unit: second) (i)  30  25 — — — — — — (ii) — — 130 90 150 170 230 190 Etching Property Good Good Good Good Good Good GoodGood Plating Step Plating Resistance Good Good Good Good Good Good GoodGood Adhesion Test (II) (N/100) 100 100 100 100 100 100 100 100 PlatingProperty Good Good Good Good Good Good Good Good Evaluation ofConductive Pattern (μm)  ≦1  ≦1  ≦1  ≦1  ≦1  ≦1  ≦1 ≦1

[0154] TABLE 7 Comparative Examples Examples 25 26 27 28 29 30 1 2Exposing/Developing Step Thickness of Predried Film (μm)  15  16  15  15 17  17  15  15 Surface Tackiness of Predried Film Good Good Good GoodGood Good Good Good Developing Property (i) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ (ii) ⊚ ⊚ ⊚ ⊚⊚ ◯ X X Adhesion Test (I) (N/100) 100 100 100 100 100 100 100 100Etching Step Resistance to Etching Solution Good Good Good Good GoodGood Good Good Removing Test of Cured Film (unit: second) (i)  15 —  17—  30  25  15  30 (ii) — 100 — 170 — — X X Etching Property Good GoodGood Good Good Good Good Good Plating Step Plating Resistance Good GoodGood Good Good Good Good Good Adhesion Test (II) (N/100) 100 100 100 100100 100 100 100 Plating Property Good Good Good Good Good Good Good GoodEvaluation of Conductive Pattern (μm)  ≦1  ≦1  ≦1  ≦1  ≦1  ≦1  ≦1 ≦1

What is claimed is:
 1. A photosensitive resin composition comprising:(A) a water-soluble photosensitive resin selected from the groupconsisting of a first resin obtained by introducing a styryl pyridiniumgroup into a polyvinyl alcohol polymer, a second resin obtained byintroducing a styryl quinolinium group into a polyvinyl alcohol polymer,and a third resin obtained by adding N-alkylol(meth)acrylamide to apolyvinyl alcohol polymer; (B) a photosensitive prepolymer having acarboxyl group and at least two photopolymerizable ethylenicallyunsaturated groups in the molecule; (C) a photopylymerization initiator;and (D) water.
 2. The photosensitive resin as set forth in claim 1,further comprising (E) a photopolymerizable ethylenically-unsaturatedmonomer.
 3. A photoresist ink for manufacturing printed wiring boards,comprising the photosensitive resin composition as set forth in claim 1.4. A photoresist ink for manufacturing printed wiring boards, comprisingthe photosensitive resin composition as set forth in claim
 2. 5. Aphotosensitive resin composition comprising: (A) a water-solublephotosensitive resin obtained by adding N-alkylol(meth)acrylamide to thepolyvinyl alcohol polymer; (B) a photosensitive prepolymer having acarboxyl group and at least two photopolymerizable ethylenicallyunsaturated groups in the molecule; (C) a photopolymerization initiator;and (D) water.
 6. A photosensitive resin composition comprising: (A) awater-soluble photosensitive resin selected from the group consisting ofa first resin obtained by introducing a styryl pyridinium group into apolyvinyl alcohol polymer, a second resin obtained by introducing astyryl quinolinium group into a polyvinyl alcohol polymer, and a thirdresin obtained by adding N-alkylol(meth)acrylamide to a polyvinylalcohol polymer; (B) a photosensitive prepolymer having a carboxyl groupand at least two photopolymerizable ethylenically unsaturated groups inthe molecule, said photosensitive prepolymer having an acid value withina range of 20 to 300 mgKOH/g; (C) a photopolymerization initiator; and(D) water.
 7. A photosensitive resin composition comprising: (A) awater-soluble photosensitive resin selected from the group consisting ofa first resin obtained by introducing a styryl pyridinium group into apolyvinyl alcohol polymer, a second resin obtained by introducing astyryl quinolinium group into a polyvinyl alcohol polymer, and a thirdresin obtained by adding N-alkylol(meth)acrylamide to a polyvinylalcohol polymer; (B) a photosensitive prepolymer obtained by adding anethylenically unsaturated monocarboxylic acid and an unsaturated orsaturated polybasic acid anhydride to a polyfunctional epoxy compoundhaving at least two epoxy groups; (C) a photopolymerization initiator;and (D) water.
 8. A photosensitive resin composition comprising: (A) awater-soluble photosensitive resin selected from the group consisting ofa first resin obtained by introducing a styryl pyridinium group into apolyvinyl alcohol polymer, a second resin obtained by introducing astyryl quinolinium group into a polyvinyl alcohol polymer, and a thirdresin obtained by adding N-alkylol(meth)acrylamide to a polyvinylalcohol polymer; (B) a photosensitive prepolymer obtained by a reactionof a compound having a photosensitive ethylenically unsaturated groupand a hydroxyl group in the molecule with a copolymer of an unsaturatedpolybasic acid anhydride and an aromatic hydrocarbon having a vinylgroup; (C) a photopolymerization initiator; and (D) water.
 9. Aphotosensitive resin composition comprising: (A) a water-solublephotosensitive resin selected from the group consisting of a first resinobtained by introducing a styryl pyridinium group into a polyvinylalcohol polymer, second resin obtained by introducing a styrylquinolinium group into a polyvinyl alcohol polymer, and a third resinobtained by adding N-alkylol(meth)acrylamide to a polyvinyl alcoholpolymer; (B) a photosensitive prepolymer obtained by a reaction of anethylenically unsaturated compound having a single epoxy group with acopolymer of a first ethylenically unsaturated monomer having nocarboxyl group and a second ethylenically unsaturated monomer having thecarboxyl group; (C) a photopolymerization initiator; and (D) water. 10.A photosensitive resin composition comprising: (A) a water-solublephotosensitive resin selected from the group consisting of a first resinobtained by introducing a styryl pyridinium group into a polyvinylalcohol polymer, a second resin obtained by introducing a styrylquinolinium group into a polyvinyl alcohol polymer, and a third resinobtained by adding N-alkylol(meth)acrylamide to a polyvinyl alcoholpolymer; (B) a photosensitive prepolymer obtained by a reaction of apolymer or a copolymer containing an ethylenically unsaturated monomerhaving an epoxy group as polymerization unit with an unsaturatedmonocarboxylic acid and one of saturated and unsaturated polybasic acidanhydrides; (C) a photopolymerization initiator; and (D) water.
 11. Aphotosensitive resin composition comprising: (A) a water-solublephotosensitive resin selected from the group consisting of a first resinobtained by introducing a styryl pyridinium group into a polyvinylalcohol polymer, a second resin obtained by introducing a styrylquinolinium group into a polyvinyl alcohol polymer, and a third resinobtained by adding N-alkylol(meth)acrylamide to a polyvinyl alcoholpolymer; (B) a photosensitive prepolymer obtained by a reaction of partsof carboxyl groups in a cellulose derivative having carboxyl groups witha compound having an epoxy group and at least one ethylenicallyunsaturated group; (C) a photopolymerization initiator; and (D) water.12. A photosensitive resin composition comprising: (A) a water-solublephotosensitive resin selected from the group consisting of a first resinobtained by introducing a styryl pyridinium group into a polyvinylalcohol polymer, a second resin obtained by introducing a styrylquinolinium group into a polyvinyl alcohol polymer, and a third resinobtained by adding N-alkylol(meth)acrylamide to a polyvinyl alcoholpolymer; (B) a photosensitive prepolymer obtained by a reaction of acompound having a single epoxy group and at least one ethylenicallyunsaturated group and one of saturated and unsaturated polybasic acidanhydrides with a cellulose derivative having carboxyl groups; (C) aphotopolymerization initiator; and (D) water.
 13. A predried filmobtained by drying the photosensitive resin composition as set forth inclaim
 1. 14. A predried film obtained by drying the photosensitive resincomposition as set forth in claim
 2. 15. A predried film obtained bydrying the photoresist ink as set forth in claim
 3. 16. A predried filmobtained by drying the photoresist ink as set forth in claim 4.